The present invention relates generally to a cotton harvester and more particularly to a cotton-conveying system for a cotton harvester.
In a cotton harvester, such as shown in U.S. Pat. Nos. 4,249,365 and 4,286,424 of common ownership with the present application, individual row units carry spindles which remove cotton from rows of cotton plants. Upright doffer assemblies doff the cotton from the spindles and direct the cotton rearwardly into a discharge compartment or suction door. The doffed cotton strikes a baffle or rear panel structure and then drops downwardly through a free fall zone to a cotton-receiving suction opening at the lower end of the discharge compartment. A duct extends upwardly from the discharge opening and connects the discharge compartment with a cotton receptacle on the harvester. A stream of air directed upwardly into the duct at a location downstream of the opening creates a vacuum at the opening and induces a draft in the compartment. The cotton is sucked through the opening and upwardly into the duct to the airstream location. The cotton is then blown into the receptacle by the airstream.
The above-described cotton-conveying system has proved to be satisfactory in most cotton-harvesting conditions but has suffered from certain limitations. In high yield cotton, a larger than normal volume of cotton impinges against the baffle or panel structure, and the cotton tends to clump and cause blockages at the bottom of the compartment, especially in damp conditions. Debris such as sap and stalks builds up on the structure to hinder cotton flow and increase the likelihood of a blockage. Although the induced draft in the compartment directs the cotton to the discharge opening, the source and direction of the draft are unpredictable and not always completely effective to prevent debris buildup and propel large volumes of cotton rearwardly through the opening.
In a four-row system such as shown in the aforementioned U.S. Pat. No. 4,249,365, or in other systems where one high volume discharge compartment receives cotton picked by two high capacity picker drums, the above-described problems are more evident. The sheer volume of cotton flowing downwardly in the compartment while harvesting high yield cotton increases the likelihood of a blockage. To alleviate debris buildup and blockages in certain field conditions, it has been necessary to reduce the ground speed of the cotton harvester and to perform frequent time-consuming cleanings of the discharge compartment, thereby decreasing the productivity of the cotton harvester.